On 8/22/05, Benoit Boissinot <[EMAIL PROTECTED]> wrote: > On Sun, Aug 21, 2005 at 06:34:48PM -0400, Jon Smirl wrote: > > This should fix it, but I'm not on a machine where I can test it. Can > > you give it a try and let me know? > > > > it works ok. > But there is still at least one problem: if ops->store returns an error, > then there will be a substraction and the write will loop (i could do it > with a store wich returned EINVAL and a 22 length string). > > I don't know if you can put a '\0' at buffer->page[count] if > count == PAGE_SIZE. > > Moreover, i think it is more correct to add only the leading > whitespace from the count because if the ops->store doesn't read > everything it will do something weird: > > For example, if we have ' 123 ' and ops->store read only one char, > then the function will return 7 (1 leading + 4 trailing + 1 read). For > the next call the buffer will be filled only by spaces which is > incorrect (it should be '23 ').
The attached version tries to fix these issues. I am still not somewhere where I can test, so please check it out. -- Jon Smirl [EMAIL PROTECTED]
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -6,6 +6,7 @@ #include <linux/fsnotify.h> #include <linux/kobject.h> #include <linux/namei.h> +#include <linux/ctype.h> #include <asm/uaccess.h> #include <asm/semaphore.h> @@ -207,8 +208,41 @@ flush_write_buffer(struct dentry * dentr struct attribute * attr = to_attr(dentry); struct kobject * kobj = to_kobj(dentry->d_parent); struct sysfs_ops * ops = buffer->ops; + size_t ws_count = count, leading = 0; + int ret = 0; + char *x; - return ops->store(kobj,attr,buffer->page,count); + /* locate trailing white space */ + while ((ws_count > 0) && isspace(buffer->page[ws_count - 1])) + ws_count--; + if (ws_count == 0) + return count; + + /* locate leading white space */ + x = buffer->page; + while (isspace(*x)) + x++; + leading = x - buffer->page; + ws_count -= leading; + + /* interface is still ambigous about this */ + /* string is both passed by length and terminated */ + if (ws_count != PAGE_SIZE) + x[ws_count] = '\0'; + + ret = ops->store(kobj, attr, x, ws_count); + + /* is it an error? */ + if (ret < 0) + return ret; + + /* the whole string was consumed */ + if (ret == ws_count) + return count; + + /* only part of the string was consumed */ + /* return count can not include trailing space */ + return leading + ret; }